Door



Q April 1940- M. A. PIXLEY 2,195,875

DOOR

Filed June 27, 1955 Y 7 Sheets-Sheet 1 5/ Z FZZ April 2, 1940.

Filed June 27, 1935 M. A. PIXLEY DOOR 7 Sheets-Sheet 5 52 III N H 39 4543 nwewraz? MIA mm A. P/AZE) 5 7 ATTO/P/Vf/J April 2, 1940. P|XLEY2,195,875

DOOR

Filed June 27, 1935 '7 Sheets-Sheet 6 J-/ 1/6. (5 Fi 7.

, Il i Ill/9 11% 147' 7' ORA t KS April 1940- M. A. PIXLEY 2,195,875

DOOR

Fild June 27; 1935 7 Sheets-Sheet '7 F/' 22. A 5

CENTER-H 49 I 49 I I CENTER-L -Q- Patented Apr. 2, 1940,

UNITED STATES PATENT OFFICE noon.

p 7 Milton A. Pixley, Columbus, Ohio Application June 27, 1935, SerialNo. 28,705

34 Claims.

The object of my invention is to provide a one piece overhead door witha counterbalancing mechanism. Y

It is my particular object to provide the dangerous part of thecounterbalancing mechanism fully enclosed'to prevent danger to life andproperty when the door is being operated.

It is a further object to provide a counterbalancing mechanism with anair cushion and air control means for regulating the movement of thedoor from one position to the other.

It is an additional object of the invention to provide means ofadjusting the counterbalancing mechanism by a simple adjustment so thatit can be accommodated to different doors and the doors to varying typesof installations without a modification of the operation of thecounterbalancing mechanism and the doors.

It is a. further object of the invention to provide a totally enclosedcounterbalancing spring mechanism to prevent injury to life or person ifthe spring breaks and to associate with the totally enclosed spring a.cylinder and piston arrangement and means of regulating the entrance andexit of air to the cylinder so as to secure a cushioning effect on thecounterbalance mechanism as the door proceeds from one position toanother.

It is an additional object to provide an overhead door that has acontinuous movement from one position to the other and which eliminatesthe dual movements now characteristic of overhead doors by whichthe'door first moves upwardly and then in an arc to a horizontalposition.

It is a further object of the invention to provide a two-part doorconsisting of the main door structure and a bottom sealing strip soarranged as to seal the bottom of the door in closed position and topermit the door at the bottom to immediately swing in a continuous arcfrom closed position to open position without the necessity of liftingthe door preparatory to such swinging movement. It is my object tothereby provide a door which can swing at the bottom outwardly andupwardly irrespective of any obstructions in front of the base portionof the door.

It is an additional object of my invention to eliminate the sealingweather strip as arranged on present day doors, in which present daydoors the upper half of the weather strip is attached to the door andthe lower half is attached to the door jambs. The attaching of the lowerhalfof the weather strip to the door jambs is objectionable as itreduces the width of the opening terfere therewith.

by the amount of the inward projection of the weather strips. When suchweather strips are made of metal, they are a constant source ofannoyance and expense as they injure the vehicles passing through thedoor opening.

It is my object to eliminate these lower half weather strips. Itis myobject to provide the upper half of the weather strip on the door in afixed position and to provide the lower half, except for an extremebottom section of minor length, by attaching it to the moving dooritself by links.

It is a further object of my invention to move one part of the'weatherstrip on the lower half of one side of the door downwardly and the otherhalf of the weather strip upwardly on the other side of the door,thereby balancing the two lower half weather strips on opposite sides ofthe door and so interconnecting them with the locking device on the dooras to permit of the movement of the weather strip halves on the doorupon the unlocking of the door preparatory to movement of the door.

It is a particular object to provide door-mounted, retractible, movableweather strips on the lower halves of the door interconnected with thedoor lock and automatically rotatable to opening position upon unlockingof the door. It is my object to provide movable weather strips ofbalanced construction, preferably interconnected with the door lock.

It is a further object to provide stationary weatherstrips at the lowercorners of the door of lesser height than the running board ofautomobiles using the door opening so as not to in- Referring to thedrawings,

Figure 1 is a rear elevation of the door with the counterbalancingmechanism removed.

Figure 2 is a section on the line 2-2 of Figure 3 showing the door inclosed position.

Figure 3 is a rear elevation of one side of the door in closed position.

Figure 4 is a section on the line 4-4 of Figure 3 showing the door inopen position.

Figure 5 is a section through the spring cylinder, air cylinder and airvalve with the door in closed position.

Figure 6 is a similar view through a portion of the spring, air andspring cylinder and air valve in the open position.

Figure 7 is a section on the line 'l'! of Figure 3 showing the door inpartially open position.

Figure 8 is a detailed inside elevation of the lower end of the springcylinder, the means of pivotally attaching it to the bottom of the door,the hinged construction of the movable leaf of the bottom of the doorand the lower stationary section or the weather strip.

Figure 9 is a section on the line 8! of Fig ure 8.

Figure 10 is a section on the line Ill-Ill of Figure 9.

Figure 11 is a section on the line ll--li of Figure 8. v

Figure 12 is a side elevation of the cable adjusting mechanism.

Figure 13 is a rear elevation thereof.

Figure 14 is a section through the cable adjusting mechanism in itsexpanded position.

Figure 15 is a section through the air check valve when the valve is inits horizontal position.

Figure 16 is a detailed, inside elevation showing the movable weatherstrip carried on the lower half of the door.

Figure 17 is a section on the line I'I|| of Figure 1.

Figure 18 is a section on the line l8-I8 of Figure 16.

Figure 19 is a section on the line |9-l9 of Figure 16.

Figure 20 is a section on the line 20-20 of Figure 16.

Figure 21 is a section on the line 2l2l of Figure 16.

Figure 22 is a diagram showing two groups of adjustments of the cable.

Figure 23 shows a position of adjustment with the door in the lowerquadrant.

Figure 24 shows a position of adjustment with the door in the upperquadrant.

Figure 25 shows the effect of the decreased pull in the lower quadrant.

This invention deals with a door of the overhead type consisting of asingle door structure, with the exception of a movable base strip orbottom strip to facilitate the movement of the door outwardly in an arewithout the necessity of first lifting the door to clear the floor. Iprovide a counterbalancing mechanism to facilitate the raising andlowering of the door and in association with the counterbalancingmechanism I provide an air cushioning device working by pressure in onedirection and by vacuum in the other direction as a snubber or brake.

I provide means of adjusting this air control, means to adjust thetension of the counterbalancing spring, and means to adjust the cableconnection between the spring and the door so that the entire mechanismmay be made in a standard form and then adjusted to each installationand easily adjusted from time to time for uniform operation, dependingupon the state of the spring and the adjustment of the air valves.

To prevent serious accidents from the breaking of this powerful springwhen it is at a position adjacent to persons or property, I enclose itin a tube, which also acts as the air cylinder, as well as theprotecting tube for the spring and a guide for the spring. The door isadapted to move from a vertical position when it is closed to ahorizontal position when it is open and to swing from one position tothe other in a continuous arc.

Referring to the drawings in detail, I is a door having a plurality ofpanels 2. This door fits within a door frame having a top 2 and sidewalls 4 that form the outline of a door opening 5. The upper corners ofthe door are provided with rollers 6 that rest in horizontally disposedtracks I adjacent the upper corners of the door.

' The door is provided on its upper edge with a metal weather strip. 8that overlaps the wall 2 of the building. The door is also provided withvertical weather strips on the upper half of the door on either sidethereof as at 8 and II. The lower halves of the door are provided withmovable metal weather strips II and I2, which are pivotally mounted onthe side walls on the inside of the door as indicated in Figures 1, 16,18, 19 and 20. The weather strips so pivotally mounted are supported ona plurality of links 13 that are pivoted at I4 to the door. These linksare connected together by a vertical portion of the strip I! that inturn is connected to a horizontal actuating pitman It. This pitman I8 ispivoted at ll to a spring actuated disk I! moved by the spring I!normally so as to withdraw the metal weather strips II and I2 inwardlybeneath the cover plates 20 and 2| and within the margin of the door soas to permit the door to swing with its lower half outwardly while itsinner half swings inwardly. When the door is in closed position, thedisk II is held against such rotation and the weather strips II and I2are in their extended position so as to overlap the door jamb. This isaccomplished by the lock 22 which has a locking bolt 22a that engagesthe disk It and retains it in position against the action of the springIS.

The lower edges of the door are overlapped and engaged by the shortvertical sections of weatherstripping 23 mounted on the door jamb but oflesser height than the running board of an automobile so they will notinterfere with an automobile. Thereby I eliminate the stationary weatherstrip on the door jamb which now is used in the doors of the prior art.Such a door strip damages the automobiles passing through the doorwayand restricts the doorway opening. By my movable strips II and i2 Icompletely eliminate this disadvantage.

C'ounterbolancina mechanism I pivotally support, preferably on eitherside as at 24 upon the bracket 25 which is mounted on the door jamb, thetube 26. A bearing 21 supports the shaft 24 in the bracket 25.

This tube is closed at its upper end by a cap 28 which is provided witha bolt 29 that extends into the interior of the tube and supports at 30a coil spring 2|. The lower end of the spring 3| is connected at 32 to asecond bolt 33 which has on its outer end an eye 34 to which is attachedthe cable 35. On 32 is mounted a pair of washers 36 which engage withthe inner side walls of the tube 28 and form a piston (Figures 2, 5 and9).

The cable passes to a permanent but adjustable anchor to which it isfastened by the retaining bolt or screw 21. This anchor is mounted uponthe side wall of the door opening on a part of the bracket 25. It willbe described in detail hereinafter.

Air control In order to provide an air cushion or brake, I provide thepiston 22. The quantity of air in the cylinder 28 is regulated by thebleed valve 20 and by the check valve 38. This valve has a chamber 40communicating through the passageway 4! with the interior of thecylinder. It isalso provided with a chamber 42 having an outside port42. A port 44 connects th chambers 40 and 42. The balls 45 and 42alternately control the port 44, depending upon the position of thevalve as the valve moves with the cylinder. Thus I provide anautomatically arse-,eva 3 controlled valve toaccomplish a braking orretarding action.

In the closing operation, a partial vacuum is formed by the piston inits travel in the cylin- 5 der defined by the tube 20, downwardly, asseen in Figures 2. and 5. In the uppermost position of the door, thetravel of the piston in the opposite direction provides a cushioningeffect for the final substantially horizontal travel of m the door bycompressing the air in the tube, the

valve position beingthat shown in Figure 6 of the drawings. The force ofthis compression acts in opposition to the tension of the springandprevents pounding or battering of the door, which would be caused bythe spring action if it were uncontrolled." The force of thiscompression increases as the door travels to its final open position;.and when the door has reached its final position, the maximumcompression force is encountered. This compression force may be variedby manipulation of bleed valve 38 although it is to be understood that.it varies, as theposition of the door changes, whatever the setting ofthe bleed valve 38 may be. This bleed valve" :6 38 also varies theabove-described-vacuum force so that the two forces, so far as the bleedvalve 38 is concerned, aredirectly proportional;- this will be furtherdescribed below. v

length of the cable '35 is greater in-thelowerquadrant positions(Figures 23, 24'and 25).than

in the upper quadrant positions due to the'spacing of the jaws 41 and 48(described. below) above the pivotpoint 24 of the tube '2. 1 increasesthe spring tension and vacuum force I in that quadrant, as will behereinafterexplained. In the lower quadrant positions of door,

I as illustrated particularly in 2, '5, "I, 23, 24 and- 25, the ball 46closes the port .44 and;

prevents the entry of air through thefea way 4| into the cylinderdefined by. the; tube 26. A partial vacuumis thus'formed'above the 1piston defined by washers, which, in conjunc' tion,with the tension ofthe spring, retards the downward movement of the piston v (Figures 2 and5), and there is thus tocable;

35 a tension equal-tothesum.of' thejvacuum force and the tension of thespring. f 'I'l1e de-' .gree' of vacuum force isv adjusted; by means-of;the bleed valve 38, asexplainedabove-and the g0 tension of. the spring-Il {may be-adjusted-by means of the bolt 58.. -It is to 'be understoodthat the-tension in theicable '35, in every tion of the door, exertsavertical forceonthe]; door due to the fact 'that there is'naturalLvavertical component for this force of the-tension;

which tension is angularly disposed with respect to the-horizontal, savein onep m n; will. he therefore understood that this tension' erts a'variable counterbalancing, eflfect on the a door, which is modified atthe upper and lower endportions of the travel of the door, by thevcushioning effect of the compression and vac? uum forces in the tube 28,as explainedabove.

The force of vacuum will be additive in the lower ing the opening of thedoor, the tube 36 becomes 7 l ure l5. When the balls'are in thisposition, the interior of the tube 38 is open to the atmosphere A. andthe spring alone exerts tension on the ca- 4 ble 35.

f j The increase in effective length of cable 35 in the lower quadrantpositions afiects the travel of the piston in tube and thus increasesthe The eflective quadrant (Figures 23, 24 and 25) untilydur 7substantially'horizontal, in which position the valve balls will takethe position shown in Figeffect of the spring in the vacuum. when thetube 3| is swung upwardly beyond the horizontal, during the operation ofthe door, the ball 45 sea-ts and closes the port 44 and thus preventsescape of air from the cylinder de- 5 fined by the tube 28, throughpassageway 4i. This air is compressed by the travel of the pistondefined by washers 36, and the force of this compression is opposed tothe tension of the spring 3|. The piston defined by the washers o 86 inits travel in the cylinder defined by the tube 26 thus, in the lowerquadrant position of the mechanism (Figures 23, 24 and 25) creates avacuum force which is additive to the force of spring tension to providetension in the cable 5 35. In the upper quadrant positions of themechanism, the piston creates compression force which is opposed to thespring. tension. In other words, in these latter positions, the tensionin cable amounts to the spring tension less the 20 f the whole and that,as the angle increases from z'ero to' 90 degrees in the lower quadrant,and

than from 90 degrees back to zero in the upper 30.

quadrant,.while the dooris being moved from closed'to open position,this vertical component '-is'varied. The tension furthervaries becausethe springftension isidependent upon Hookes 9 law, and still furtherbecause the above-described 88- vacuum and compression forces producedby the 'DiStOlIdn the cylinder defined by tube 26 in.-.

crease as the piston travels toward each reg'spective end of the-tube 2'during the opening operation. It will be seen that the counterbalancmingeflfect of my devlce' is dependent upon thetension in the cable 35,which tension'varies, as 3 pointed out above, and which maybecontrolled,

'pointed'out above, .by manipulationcf the bleed valve 38 and :bolt 29.Further means for controlling the characteristics of' thiscounterbalancing eflecty'whichmeans are operable to adjust the cables35, as may be desired, will be described below. Bythis means, describedbelow, the increase ineffective length of cable 35, which directlya'ifects the-spring tension and vacuum force in the lower quadrant.positions of the fdoor, may bewidely aried for the-purpose- .of, furthercontrolling the operating characteristics of my'device.

, 7 C'dbleyadjustin'g, mechanism I Referring to the detailed. drawingsinFigures 12, 13am 14, it will' be noted that-aplurality I i .ofadjustmentsare provided, with respect to- 0 the. effective length of thecable 35 and its anchorage at t1. The cable .35 passes over thearcuateends of thejaw. members 41 and 48.

"These jaw members pivotedon one another upon'the pivot pin 48 which iscarried in the flange 50. of the bracket 25. The screw 5| on the member48 engages onits end in the socket 52 the member 41 and determines. howclose these two members may approach one another.

Thescrew bolt 53 has a nut 54 engaging. with the member 41. Screw 53moves the jaws 41 and 48 forward and backward over a sector having itscenter in the'bolt 49 irrespective of whether or not laws .41 and 48 areclosed or spread apart.

In order to make the above clear, I refer to Figure 22 showing twogroups: Group A with jaws closed; Group B with jaws spread.

It will be noted AI shows the jaws closed and forward. A2 shows the jawsclosed and perpendicular. A3 shows the jaws closed and rearward. B Groupshows these same three positions with the jaws spread. The sector Cshows the movement of the jaws forward and backward. Sector D shows thespreading movement of the jaws. Intermediate positions are alsoobtainable in both groups.

It will be noted the center line H shows the highest position of thebolt 49 and center line L shows the lowest position of the bolt 49, thishigh and low adjustment being obtained by bolt or screw engaging inthreaded position of 55.

In properly counterbalancing a door it is necessary to be able to makeseveral adjustments; first, to increase or decrease the cable pull uponthe spring over the whole circumference of the semicircle described bythe end of the radial arm; second, to increase or decrease the pull ofthe cable on the spring for the lower quadrant; and third, to increaseor decrease the pull of the cable on the spring in the upper quadrant.

It must be possible to increase or decrease the cable pull on the springin one quadrant without changing the cable pull in the other quadrant.This is accomplished by varying the forward or rearward position of jaws41 and 48 and also by spreading these jaws, moving the jaws forward froma perpendicular position decreases the cable pull in the lower quadrantand increases the pull in the upper quadrant, but by moving the jaw 4!forward and retaining jaw 48 in a vertical position would not change thecable pull in the upper quadrant; but by moving jaws rearwardly from aperpendicular position the conditions described above are reversed.

With reference to Figure 23, the solid lines represent a position in thelower quadrant. I have shown a force diagram in solid lines whichcorresponds to that position. It will be noted lbs. is A; of the doorweight acting vertically downward, which gives a cable pull of 320 lbs.If the jaws are moved forward as shown in the dot and dash lines thecable pull becomes 255 lbs.

Figure 24 shows the door positioned in the upper quadrant, theperpendicular jaws in solid lines and the forward position of the jawsin dot and dash lines which is identical with the position in Figure 23.This more acute angle increases the cable pull on the spring.

Figure 25 shows the effect of the decreased pull in the lower quadrantidentical with the dot and dash lines on Figure 23. The solid line showsthe same cable pull as shown on Figure 24 and this is obtained byspreading the jaws 41 and 48. In other words, it decreases the cablepull in the lower quadrant without increasing the cable pull in theupper quadrant.

The vertical position of these two members is determined by theadjusting screw or screw bolt 55 which is mounted on the bracket 25 andactuates the block 56 between the guides 51. Thus a spreading adjustmentand an upand-down adjustments are possible with this construction. .Theshifting of the point of attachment of the cable changes the angularpull and consequently the strain upon the cable, thereby allowing a widevariation for different door weights by using the same spring. Theoriginal spring tension is accomplished by adjusting the bolt 2! as thatbolt is threaded into the head 20 carrying the spring 3|.

The lower end of the tube 28 is pivotally mounted as at 58 on a bracket50 mounted on the lower inner face of the door. This bracket has mountedupon it the guide roller II for guiding the cable 25.

The bracket also has pivoted at 2 a hinged plate 63 that carries thebottom strip 84 that interengages with the bottom of the door. When thedoor swings outwardly this bottom strip breaks away from the door andpermits the free opening of the door. When the door assumes itshorizontal position, the bottom strip 64 is held in horizontal positionas a part of the door by the latch member 65 which is pivoted upon thebracket 68 as at 51. The member 65 is provided with a rib 65a thatengages with the arcuate portion "a so as to hold it in such positionthat when the door is open it supports the bottom strip 84 in ahorizontal position.

Method of operation When the door is unlocked by unlocking the lock 22,the disk 5 rotates under the influence of the spring [9 and moves theweather strips Ii and I2 inwardly. By pushing upon the door, the lowerhalf moves outwardly with the bottom strip moving about its hinge 62.The upper half moves inwardly guided by the rollers 6 in the horizontaltracks I. The spring and air cushion means counterbalance this movement,as pointed out above.

When the door approaches its final open position, the air cushion effectof the compression in tube 26 snubs or brakes the final movement of thedoor into pomtion in a horizontal position parallel to the roof of theroom. Duri s this operation the balls 45 and 45 have changed position asindicated by the several views. When the reverse operation takes place,the counterbalancing mechanism again goes into play and the airmechanism, due to its vacuum action at the end of the downward movementof the door,

serves to cushion the movement of the door to its home position, asclearly pointed out above.

While I have described in detail the various variable forces which maycontrol the operating characteristics of the device in moving fromvertical or closed to horizontal or open position, it is to beunderstood that in the reverse operation, the cycle will be reversed andthe vacuum force will provide a cushioning eifect and operate in thesame direction as the spring, as the eiIective length of the cable 25 isincreased, the piston being forced toward the lower end of the tube 26,as seen in Figure 5. Due to the various adjusting means, hereinbeforedescribed,

the operating characteristics may be changed as may be desired and toaccommodate doors varying widely in weight. It is to be understood thatmy device in operation provides a desirable varying counterbalancing ofthe door during the cycle of operation, and in addition providescushioning means to prevent pounding, battering, and other destructiveaction which would otherwise occur due to the inertia of the door.

It will be understood that it is desired to comprehend within thisinvention such modifications as may be necessary to adapt it to varyingconditions and uses.

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent, is:

1. In combination, a door adapted to close an opening in a building, acounterbalance and lifting mechanism comprising a radial arm and a vflexible tension member connected thereto and. to the building andpassing around a pulley on the door for counterbalancing and guiding thedoor from open to closed position and vice versa, and means on the doorand building for guiding the door in its movements.

2. In combination, a door adapted to close an opening in a building, acounterbalance and lifting mechanism comprising a radial arm and aflexible tension member connected to the radial arm and to the buildingand passing around a pulley on the door in supporting relation forcounterbalancing and guiding the door from open to closed position andvice versa, means on the door and building for guiding the door in itsmovements, and means adiustably secured to the building for regulatingthe relationship of said counterbalance and lifting mechanism withrespect to the building and the door.

3. In combination, a door adapted to close an opening in a building, ahorizontally disposed track located at right angles to the door when thedoor is closed, rollers on the door engaging the track, guiding armspivoted to the building and to the door for guiding the end of the dooropposite from. the ends supported on the tracks,

and yielding means including a pneumatic cushioning device forinterconnecting said door and its guiding means-with the building forcounterbalancing the door.

4. In combination, a door adapted to close an opening in a building, ahorizontally disposed track located at right angles to the door when thedoor is closed, rollers on the door engaging the track, guiding armspivoted to the building and to the door for guiding the end of the dooroppositeirom the ends supported on the tracks, yielding means includinga pneumatic cushioning device for interconnecting said door and itsguiding means with the building for counterbalancing the door, and meansfor adjusting the relationship of said counterbalancing means withrespect to the door and the building.

5. In combination, a door, acounterbalance and lifting mechanism,rollers on a part of said door, track-means forguiding a part 01' thedoor, and pneumatically controlledmeans for cushioning the movement ofsaid door at the extremes of its open and closed positions.

,6. In combination, a door, a counterbalance and lifting mechanism,rollers on a part of said door, track means for guiding a part of thedoor, said counterbalance and lifting mechanism being adapted to guideanother part of said door, and pneumatically controlled means forcushioning the movement of said door at the extremes of its open andclosed positions.

7. In combination, a door, a counterbalance and lifting mechanism,rollers on a part of said door, track means for guiding a part of thedoor, said counterbalance and lifting mechanism being adapted to guideanother part of said door, means to adjust the relationship of thecounterbalance and lifting mechanism with respect to the door, andpneumatically controlled means for cushioning the movement of said doorat the extremes of its open and closed positions.

8. In combination, a door, a counterbalance and lifting mechanism,rollers on a part of said door, track means for guiding a part of thedoor, means to adjust the relationship of the counterbalance and liftingmechanism with respect to the door,

and pneumatically controlled means for cushioning the movement of saiddoor at the extremes of its open and closed positions.

9. In combination, a door for closing a door opening in a building, acounterbalance and lifting mechanism connecting said building and saiddoor, means on said building for guiding said door from one position toanother, means of adjustably securing said counterbalance and liftingmechanism to the building for modifying the relationship thereof to thedoor, and pneumatically controlled means for cushioning the movement ofsaid door at the extremes of its open and closed positions.

10. In combination, a door adapted to close an opening in a building, acounterbalance and lifting mechanism comprising a radial arm and aflexible tension member connected to the building and to thecounterbalance and passing over a pulley on the door forcounterbalanclng and guiding the door from open to closed position andvice versa, means on the door and building for guiding the door in itsmovements,and pneumatically controlled means for cushioning the movementof said door at the extremes of its open 26 mechanism with respect tothe building and the door, and pneumatically controlled -means forcushioning the movement of said door at the extremes of its open andclosed positions.

'12. In combination, a door adapted to close an openingin a building, ahorizontally disposed track located at right angles to the door when thedoor is closed, rollers on the door engaging the track, guiding armspivoted to the building and to the door for guiding the end or the dooropposite from the ends supported on the traclrs, and pneumaticallycontrolled means for cushioning the movement of said door at theextremes of its open and'closed positions.

13. In combination, a door adapted to close an opening in a building, ahorizontally disposed track located at right angles to the door when thedoor is closed, rollers on the door engaging the track, guiding armspivoted to the building and to the door for guiding the end of the dooropposite from the ends supported on the tracks, yielding means forinterconnecting said door and its guiding means with the building forcounterbalancing the door, and pneumatically controlled means forcushioning the movement of said door at the extremes of its open andclosed positions.

14. In combination, a door adapted to close an opening in a building, ahorizontally disposed track located at right angles to the door when thedoor is'closed, rollers onthe door engaging the track, guiding armspivoted to the building and. to the door for guiding the end of the dooropposite from the ends supported on the tracks, yielding means forinterconnecting said door and its guiding means with the building forcounterbalancing the door, means for adjusting the relationship of saidcounterbalancing means with respect to the door and the building, andpneumatically controlled means for cushioning the movement of said doorat the extremes 0! its open and closed positions.

15. In combination, with a door, a counterbalancing mechanism comprisinga spring connected to a building at one end and to a cable passingaround a pulley rotatably mounted on the door at the other end, andmeans for enclosing said spring.

16. In combination, a building having a door opening, a door, acounterbalancing spring connected to said building and to a cablepassing in supporting engagement around a pulley mounted on said door, atube supporting said spring at one end, guiding it at the other end, andenclosing it from end to end.

17. In combination, a building having a door opening, a door, acounterbalancing spring connected to said building and to a cablepassing about a rotatable pulley on said door, a tube supporting saidspring.at one end, guiding it at the other end and enclosing it from endto end, means for pivoting said tube to the building adjacent one end,and means to pivotally connect the tube to the door at the other endwhereby the tube serves to guide the door in its movement and to encloseand guide the spring in its movement.

18. In combination with a building having a door opening, a door, acounterbalancing mechanism for counterbalancing said door in itsmovements comprising a spring supported in a casing pivotally connectedto the building and connected to a flexible tension member passingaround a pulley on the door.

19. In combination with a building having a door opening, a door, acounterbalancing mechanism for counterbalancing said door in itsmovements comprising a spring connected to the building and the door,means for enclosing said spring,

means associated with said spring to form a piston in said enclosingmeans, and an air valve means for regulating the inlet and the egress ofair to the spring enclosing means.

20. In combination with a building having a door opening, a door, a tubepivoted on the building at one end, means for supporting a spring on oneend 01. said tube within the tube, a cable connected to the other end ofthe spring and passing around a pulley on the door, and roller guidemeans for guiding said cable to a point on the building adjacent thepivoted end of the tube.

21. In combination with a building having a door opening, a door, a tubepivoted on the building at one end, means for supporting a spring withinthe tube from one end thereof, a cable connected'to the other end of thespring, and roller guide means on said door for guiding said cable to apoint on the building adjacent the first end of the tube at a pointabove the pivotal support of the tube on the building.

22. In combination with a building having a door opening, a door, a tubepivoted on the building at one end and to the door at the other end,means for sup rting a spring on one side of said tube within the tube, acable connected to the other end of the spring, roller guide means forguiding said cable to a point on the building adjacent the first end 01'the tube at a point above the pivotal support of the tube on thebuilding, and means to adjust the relationship 01 the cable to thebuilding by the lateral movement of said adjusting means.

23. In combination with a building having a door opening, a door, a tubepivoted on the building at one end and to the door at the other end,

means for supporting a spring on one side of said tube within the tube,a cable connected to the other end of the spring, roller guide means forguiding said cable to a point on the building adjacent the first end oi.the tube at a point above the pivotal support of the tube on thebuilding, and means to adjust the relationship of the cable to thebuilding by the lateral movement of said adjusting means and by thevertical movement of said adjusting means.

24. In combination with a building having a door opening, a door, meansmounted on the building for pivotally supporting a spring tube,

means for pivotally connecting said tube to the bottom of the door,yielding means in said tube supported thereby, a cable connected to saidyielding means, means for guiding said cable to a point above the top ofsaid tube, and means for attaching said cable to the same means thatpivotally support said tube.

25. In combination with a building having a door opening, a door, meansmounted on the building for pivotally supporting a spring tube, meansfor pivotally connecting said tube to the bottom of the door, yieldingmeans in said tube supported thereby, a cable connected to said yieldingmeans, means for guiding said cable to a point above the top of saidtube, means for attaching said cable to the same means that pivotallysupport said tube, and means for laterally adjusting said cableattaching means to regulate the position of said cable with respect tothe door and the building.

26. In combination with a building having a door opening, a door, meansmounted on the building for pivotally supporting a spring tube, meansfor pivotally connecting said tube to the bottom 01' the door, yieldingmeans in said tube supported thereby, a cable connected to said yieldingmeans, means for guiding said cable to a point above the top of saidtube, means for attaching said cable to the same means that pivotallysupport said tube, means for laterally adjusting said cable attachingmeans to regulate the position of said cable with respect to the doorand the building, and means for eiIecting a vertical adjustment of thecable attaching means.

27. A new article of manufacture for use with a counterbalanced doorcomprising a bracket, pivoted jaws thereon for supporting one end of acable, and means for adjustably spreading said jaws to regulate thelength of the cable.

28. A new article of manufacture for use with a counterbalanced doorcomprising a bracket, pivoted jaws thereon for supporting one end of acable, means for adjustably spreading said jaws to regulate the lengthof the cable, and means for vertically adjusting the position of saidjaws for further adjusting the position or the cable.

29. A new article of manufacture for use with an overhead doorcomprising a bracket, a pair of jaws pivoted on one another, means foradjusting the relationship of said jaws with respect to one another,means for supporting the pivot for said jaws slidably on said bracket,and means for vertically adjusting said jaws as a unit on said bracket.

30. A new article 01' manufacture for use with an overhead doorcomprising a bracket, a pair of jaws pivoted on one another, means foradjusting the relationship of said jaws with respect to one another,means for supporting the pivot for said jaws/slidably on said bracket,means for vertically adjusting said jaws as a unit on said' bracket, andmeans for positioning one oi. said jaws in its swinging movement withrespect to said bracket.

31. A new article of manufacture for use with an overhead doorcomprising a bracket, means for adjustably supporting a pair of pivotedjaws on the upper end of said bracket for adjustably positioning a cableattached to one of said jaws and supported by both of them, andmeans onthe lower end of said bracket for pivotally supporting a. tubecontaining a spring connected to said cable whereby the tension on thespringv and the position of the cable may be adjusted with respect tosaid bracket.

32; In combination, a door, a building having a door opening, a springenclosing tube pivoted on the building and on the door, a spring thereinconnected to one end of the tube which is closed,

a piston on the other end of the spring, a cable.

connected to said piston, means for guiding said cable from the open endof the tube to a point on the building, an air valve mounted on saidtube comprising a plurality of chambers having a communicating port,balls in said chambers, a port from one chamber to the tube, and a portfrom the other chamber to the outside atmosphere whereby as said tubeand door move from one position to the other, alternate compression andsuction will be created in said tube to act as a shock absorber andbracket to cushion the movements of said door.

33. In combination, a door, a building having a door opening, a springenclosing tube pivoted on the building and on the door, a spring thereinconnected to one end of the tube which is closed,

a piston on the other end of the spring, a cable connected to saidpiston, means for guiding said cable from the open end of the tube to apoint on the building, an air valve mounted on said tube comprising aplurality of chambers having a communicating port, balls in saidchambers, a port from one chamber to the tube and a port from the otherchamber to the outside atmosphere whereby as said tube and door movefrom one position to the other, alternate compression and suction willbe created in said tube to act as a shock absorber to cushion themovements of said door, and an air valve in the closed end of said tubefor regulating the air supply therein.

34. In combination, a door, a building having a door opening, a springenclosing tube pivoted on the building and on the door, a spring thereinconnected to one end of the tube which is closed, a piston on the otherend or the spring, a cable connected to said piston, means for guidingsaid cable from the open end of the tube to a point on the building, anair valve mounted on.

said tube comprising a plurality of chambers having a communicatingport, balls in said chambers, a port from one chamber to the tube and aport from the other chamber to the outside atmosphere whereby as saidtube and door move from one position to the other, alternate compressionandsuction will be created in said tube to act as a shock absorber tocushion the movements of said door, an air valve in the closed end ofsaid tube for regulating the air supply therein, and means for adjustingthe position of said cable in its attachment on the building.

MILTON A. PIXLEY.

